Ferdinand arnold ludwig de gruyter



(No Model.)

F. A. L. DE GRUYTER.

APPARATUS FOR RAISING AND LOWERING BOATS.

No. 407,891. Patented July 30, 1889.

dimm

UNITED STATES ATENT OFFICEe FERDINAND ARNOLD LUDIVIG DE GRUYTER, OE AMSTERDAM, HOLLAND.

APPARATUS FOR RAISING AND LOWERING BOATS.

SPECIFICATION forming part of Letters Patent No. 407,891, dated July 30, 1889.

Original application filed July 24, 1888, Serial No. 280,934. Divided and this application iiled January 2, 1889, Serial No. 295,217. (No model.) Patented in England View 211, 1888, No. 7,681; in France June 25, 1888, No. 191,4.-15; in Sweden July 2,1888, No.1,682; in Norway July 9, 1888, No. 1,028; in Belgium July 10,1888,No. 82,514; in Italy September 30, 1888, XLVII, 119; in Spain October 2, 1888, No. 8,482; in Austria-Hungary October 26, 1888, No. 30,047. andin GanadaNovember 2,1888,

To all whom t 711,@ 1/ concern:

Be it known that I, FERDINAND ARNOLD LUDWIG DE GRUYTER, a subject of the King of Holland, residing at Amsterdam, in the Kingdom of Holland, have invented Improvements in Apparatus for Raising and Lowerequipped and manned, to be easily raised clear of the chocks or lowered onto them.

This application is iiled asadivision of my pending application for United States Patent iiled July 24, 1888, Serial 180,280,984..

The present application is intended to claim the second form or species of apparatus hereinbefore mentioned, as subject-matter taken out of the other specification.

In order that the nature of the present invention may be readily understood, reference is had to the accompany drawing, which illustrates in elevation part of a davit with boat raising and lowering apparatus according to this invention suspended therefrom.

1 is part of a davit, or it may be a rod or bar connected therewith, formed with an eye 2, to which is hinged at 8 the upper block of lowering-tackle, that may be ot the ordinary kind, and which comprises in the example shown a pair of pulley-blocks e.

5 is a rod formed with ri ght-and-lett-handed screw-threaded portions, upon which are iitted correspondingly screw -threaded nuts 6 6*. The upper nut 6 is connected by plates, or by a link or stirrup 7 to the frame of the lower tackle-block, the lower nut being similarly connected to the boat or to ahook or ring carried by it.

The screw-threaded rod is provided witha hand-lever 8, by turning` which the lower nut can be caused to approach or recede from the upper one to raise or lower the boat connected thereto.

Tit-l1 the arrangement described, by turning the hand-lever 8, and consequently the rightand-left-handed screw-threaded rod 5, a boat suspended to the lower nut 6* will be raised or lowered, according to the direction in which the screw is turned. Assuming a loaded boat to be on the chocks and each ottwo davits to be iitted with apparatus of the kind hereinbefore described, if the two screw-threaded rods be turned simultaneously the boat can be raised from the chocks. Then it can be worked out, and afterward lowered over the ships side in the ordinary way.

What I claim is- 1. In an apparatus for raising and lowering ships boats, the combination of loweringtackle, and a rod formed with right-and-lefthanded screws, correspondingly screw-threaded nuts fitted thereon, said rod being capable of rotation relatively totsaid nuts, one ot said nuts being suspended from said loweringtackle and the other adapted to be connected to a boat to be Araised and lowered, for the purpose specified.

2. In apparatus Jfor raising and lowering` ships boats, the combination of a pair of pulley-blo(,ks, aA right and lef t handedscrewthreaded rod, and correspondingly screwthreaded nuts, through which said rod can be caused to work, one of said nuts being connected to tlielower pulley-block and the other adapted to be connected to aboat tobe raised and lowered, for the purpose specified.

8. In apparatus for raising and lowering ships boats, the combination of a davit, lowering-tackle carried thereby, a rod formed with right-and-left-handed screw-threads, and correspondingly-formed nuts arranged thereon, one of which is suspended from said lowering-tackle and the other provided with means-such as bars -capable of being connected with a boat, said rod being capable of rotation relatively to said nuts, substantially as described, Jfor the purpose speciied.

f1. In apparatus for raising and lowering threads, a lever for rotating the said rod, and nuts 6 6*, adapted to work on said rod, but prevented from turning with reference thereto, one of said nuts being connected to said lowering-tackle and theother being adapted to be connected with a boat to be raised or lowered. l

In testimony whereof I ha e signed my name to this specification in the presence of two subscribing witnesses.

FERDINAND ARNOLD LUDWIG DE GRUYTER. Vitnesses: A. S. WooEN, G. VANDER MEULER,

Both of Amsterdam. 

